package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT; ;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    //阻塞队列
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    //线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR =  Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHander());
    }

    private class VoucherOrderHander implements Runnable {
        @Override
        public void run() {
            while (true) {
                //1.获取队列中的订单信息
                try {
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("订单处理异常",e);
                }
            }
        }
        /*
        * 订单处理
        * */
        private void handleVoucherOrder(VoucherOrder voucherOrder) {
            //获取用户id
            Long userId = voucherOrder.getUserId();
            //创建锁对象
            RLock lock = redissonClient.getLock("lock:order:" + userId);
            //获取锁
            boolean isLock = lock.tryLock();
            //判断获取锁成功
            if(!isLock){
                //获取锁失败，返回错误或重试
                log.error("不允许重复下单");
                return;
            }

            try {

                proxy.createVoucherOrder(voucherOrder);
            } finally {
                //释放锁
                lock.unlock();

            }
        }
    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        //2.判断结果是为0
        int r = result.intValue();
        if (r != 0) {
            //2.1 不为0，代表没有购买资格
            return Result.fail(r==1 ? "库存不足":"不能重复下单");
        }
        //2.2 为0 ，有购买资格，把下单信息保存到阻塞队列中
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.3订单id
        Long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //2.4用户id
        voucherOrder.setUserId(userId);
        //2.5代金券id
        voucherOrder.setVoucherId(voucherId);
        //2.6 放入阻塞队列
        orderTasks.add(voucherOrder);

        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //3.返回订单id
        return Result.ok(orderId);
    }

@Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //5.一人一单
        Long userId = voucherOrder.getUserId();

            //5.1查询订单
            Long count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
            //判断是否存在
            if (count > 0){
                //用户已经购买过
                log.error("用户已经购买过一次了");
                return;
            }
            //6.扣减库存
            boolean success =  seckillVoucherService.update()
                    .setSql("stock= stock - 1") //set stock = stock -1
                    .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0)// where id =? and stock = ?
                    .update();
            if (!success){
                //扣减失败
                return;
            }
            save(voucherOrder);
    }
    /*public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
            //尚未开始
            return Result.fail("秒杀尚未开始");
        }
        //3.判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已结束");
        }
        //4.判断库存是否充足
        if (voucher.getStock() < 1){
            //库存不足
            return Result.fail("库存不足！");
        }

        Long userId = UserHolder.getUser().getId();

        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock(stringRedisTemplate, "order:" + userId);
        RLock lock = redissonClient.getLock("lock:order:" + userId);

        //获取锁
        boolean isLock = lock.tryLock();
        //判断获取锁成功
        if(!isLock){
            //获取锁失败，返回错误或重试
            return Result.fail("一个人不允许重复下单");
        }

        try {
            //获取代理对象（事务）
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            //释放锁
            lock.unlock();

        }
    }*/
    /*@Transactional
    public  Result createVoucherOrder(Long voucherId) {
        //5.一人一单
        Long userId = UserHolder.getUser().getId();

            //5.1查询订单
            Long count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            //判断是否存在
            if (count > 0){
                //用户已经购买过
                return Result.fail("该用户已经购买过一次！");
            }
            //6.扣减库存
            boolean success =  seckillVoucherService.update()
                    .setSql("stock= stock - 1") //set stock = stock -1
                    .eq("voucher_id", voucherId).gt("stock",0)// where id =? and stock = ?
                    .update();
            if (!success){
                //扣减失败
                return Result.fail("库存不足");
            }
            //7.创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            //7.1订单id
            Long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            //7.2用户id
            voucherOrder.setUserId(userId);
            //7.3代金券id
            voucherOrder.setVoucherId(voucherId);
            save(voucherOrder);
            //8.返回订单ID
            return Result.ok(orderId);
    }*/

}
